LAKE LEMAN

Lake Geneva in figures

580 km2

Lake area

200.2 km

Length of the banks

309.7 m

Maximum depth

89 km3

Average volume

372 m

Average altitude
of the water body

11.3 years

Dwell time
theoretical waters

8,000 km2

Watershed area
from Lake Geneva*

1'400'847

Permanent population
in the watershed**

COMPLETE MATERIAL SAFETY DATA SHEET

*The Lake Geneva watershed is the entire territory where surface water flows into Lake Geneva. It extends mainly across Switzerland (cantons of Vaud, Valais, Geneva and Fribourg) and France (departments of Haute-Savoie and Ain). It is fed by several rivers, including the Rhône , its main tributary, as well as the Arve, the Dranse, the Venoge and the Aubonne.

**Data for France: 2017 – Data for Switzerland: 2018

The measuring station

Lake Geneva is regularly monitored at SHL2, the measuring station located at the lake's deepest point (309 m).

Measurement campaigns are carried out by the Centre alpin de recherche sur les réseaux trophiques et les écosystèmes limniques (CARRTEL, Université Savoie Mont Blanc, INRAE, Thonon-les-Bains, France). Water temperature is measured continuously between the surface and the bottom of the lake using a probe. The quantities of oxygen and algae suspended in the water (phytoplankton) are measured from water samples taken at various depths between the surface and the lake bottom. Surface water transparency is measured with a Secchi disk.

Data for 2021 and previous years have been validated and can be downloaded from the OLA Lake Observatory website. Data for 2022 and 2023 are provisional.